Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are enzymes found primarily inside liver cells, where they assist in converting food into energy. When the liver is injured or inflamed, these enzymes leak out of damaged cells and enter the bloodstream, resulting in elevated levels detected during a standard blood test. High readings of ALT and AST signal liver stress. The most effective way to lower these levels is to address the underlying cause of the cellular damage, often through specific changes to diet and lifestyle.
Identifying and Managing the Root Cause of Elevation
Lowering liver enzymes requires resolving the condition causing liver cells to release their contents into the blood, rather than masking symptoms. The most common driver of elevated enzymes is Non-Alcoholic Fatty Liver Disease (NAFLD), characterized by excess fat buildup in the liver. This fat accumulation causes inflammation, leading to cell damage and elevated ALT and AST readings.
For individuals with NAFLD, enzyme reduction primarily involves removing excess fat from the liver tissue. Even modest weight loss (5 to 10% of total body weight) can significantly reduce liver fat and inflammation, leading directly to lower enzyme levels. Reducing the stressor allows the highly regenerative liver to begin the repair process.
Alcohol consumption is another cause, as it is directly toxic to liver cells and causes inflammation. Eliminating or severely limiting alcohol intake is a necessary first step for recovery in these cases.
Certain medications and herbal supplements can also induce liver stress. Common culprits include some cholesterol-lowering drugs (statins) and the pain reliever acetaminophen, particularly when taken in high doses. If a drug is suspected, a healthcare provider must review the regimen to determine if the medication can be safely discontinued or replaced.
Targeted Nutritional Strategies
Dietary changes support the lowering of ALT and AST levels by reducing liver fat and inflammation. A focused nutritional strategy restricts harmful compounds while incorporating protective foods. Restricting refined carbohydrates and added sugars, especially fructose, is important because the liver readily converts these into fat.
Eliminating highly processed foods and sugary beverages (like soda and fruit juices) removes major sources of liver-stressing fats and sugars. Alcohol consumption must also be minimized, as the liver prioritizes metabolizing alcohol, which causes cellular damage and interferes with vital functions. Avoiding these substances helps halt fat accumulation and inflammation.
Regular coffee consumption has shown a protective effect on the liver and is associated with lower ALT and AST levels. The antioxidants in coffee help prevent fat and collagen buildup in the liver tissue. Drinking two to four cups of coffee per day often provides the most significant liver benefits.
Increasing dietary fiber through whole grains, fruits, and vegetables helps regulate blood sugar and cholesterol, reducing the metabolic burden on the liver. Incorporating healthy fats, such as omega-3 fatty acids found in fatty fish like salmon, reduces liver fat and inflammation due to anti-inflammatory properties. Olive oil, rich in monounsaturated fats, also helps reduce fat accumulation.
Modifying Lifestyle and Activity Levels
Achieving and maintaining a healthier body weight is the most effective non-pharmacological intervention for reducing liver enzyme levels. Weight loss does not need to be extreme; a sustained reduction of just 5 to 10% of body weight often leads to a significant decrease in liver fat and a corresponding drop in enzyme readings. This fat reduction relieves liver stress and allows the organ to begin healing.
Regular physical activity further supports this process, even without substantial weight loss. Engaging in 150 minutes of moderate-intensity exercise weekly (such as brisk walking or cycling) reduces ALT levels in individuals with NAFLD. This benefit is partly independent of weight loss, providing direct anti-inflammatory effects on the liver.
Physical activity improves insulin sensitivity, which is often impaired when liver enzymes are elevated. Improved insulin sensitivity helps reduce the amount of fat the liver stores, lessening the strain on the organ. Both aerobic exercise and resistance training contribute to this metabolic improvement.
Other lifestyle factors also support liver health. Managing chronic stress and ensuring adequate sleep help regulate hormones that influence metabolic function and inflammation. These behavioral changes work synergistically, allowing the liver to recover and elevated ALT and AST levels to normalize.